The 15-year-old's mother found an alarming MySpace conversation between her son and a woman using the screen name "I Love My Shawty" -- the conversation hinted at a sexual encounter between the boy and the woman, said police.

The teen told his mom that Groesbeck was "I Love My Shawty." The teen knew Groesbeck because she lived in the same apartment building as his dad, said investigators.

The mom reported the posts to police on March 12 so they could investigate.

Investigators found that Groesbeck and the boy engaged in sexual relations in Feb. 2009 while the boy was visiting his father at the Laurel Village apartments in Laurel, Del.

Police arrested Groesbeck last Friday.

Further investigation revealed that Groesbeck allegedly also had sexual relations with two 14-year-old boys on various occasions from March 2008 to Feb. 2009.

All the attacks happened inside her home, said police.

Groesbeck was charged with five counts of third-degree rape and eight counts of second-degree unlawful sexual contact, said Delaware State Police.